The Burro Fire grew an estimated 57 acres on Tuesday and Wednesday, but remained at 40 percent containment, firefighters said.
Most of the growth occurred in the northwest part of the fire and near the junction between the Bear Creek and Little Bear Creek trails, public information officer Andy Lyon said. The fire was more active Tuesday than it was over the weekend, which he blamed on a brief alignment of higher temperatures, drier fuel and wind blowing behind the flames as they moved uphill. On Wednesday, it backed up in the canyon and burned all the way to a fire line near the firefighters’ base camp.
While the fire’s close proximity to the camp made for some dramatic photos, Lyon said it stayed behind the bulldozer line. Because the wind was blowing in the opposite direction, the burning trees only dropped their embers downhill, he said.
The fire remained 40 percent contained as hand and chipper crews continued to secure the fire lines on its western perimeter on Thursday.
An infrared flight conducted at 2:21 a.m. Thursday showed the fire has covered 3,836 acres. Apart from the new growth areas, the burned region contained only isolated heat sources, the flight log said.
Lyon said Wednesday morning that he expected more activity this week as temperatures rise.
“Yesterday it got a little active in one area and burned a few trees and then stopped,” he said. “We might see that again today.”
Sure enough, more smoke was visible Wednesday afternoon as temperatures in the Bear Creek Trail region climbed into the 70s. Lyon said heat and dryness are contributing to the fire’s growth. Humidity in the region typically goes up after sundown, but Wednesday night saw only 29 percent humidity, Lyon said.
“The normal nighttime damper is not there,” he said.
The small Type 3 crew of firefighters still assigned to the Burro are focusing on “tidying up” the fire lines, Lyon said, removing fuel sources and improving roads near the south and northwest divisions, rather than putting out the existing flames. Since the June 16 and 17 rains slowed the fire’s spread, crews have largely relied on natural containment, helped by the rocky, high-elevation terrain on the fire’s northeast side.
But if the fire does flare up again, Lyon said hand crews are making sure the fire lines will be ready for a fresh attack on the flames.
The estimated cost of the fire has grown to $2.6 million, up from $2.5 million on Monday. About 56 personnel were working on it as of Wednesday morning, but Lyon said he expected that number to continue to fall. Members of the Interagency Emergency Management Team that responded to the fire commit to 14 days at each wildfire, and they reached the 14-day mark on Monday. But Lyon said it’s common for fire crews to stay longer than 14 days if needed. He expected some crews to remain at the Burro Fire for at least another week.
After Thursday, Dolores High School will no longer be used as the crews’ incident command center, as it has been since June 11. Lyon said firefighting efforts will continue to scale down unless the flames cross one of the fire lines, in which case more personnel will be called in.
As of Thursday morning, the National Weather Service predicted sunny, warm weather for the San Juan Mountains through Sunday, with no precipitation in the forecast. Friday’s forecast called for sunny weather with a high of 75 degrees and a southwest wind reaching up to 15 mph in the afternoon.
A red flag warning will remain in effect throughout Montezuma and Dolores Counties until 8 p.m. Friday.
The San Juan National Forest has reopened most trails and roads, including the shoreline of McPhee and House Creek campgrounds and the House Creek Road and boat ramp.
Some areas near the Burro and 416 fires remain closed to public entry, including segments of the Colorado Trail.